1. Field of the Invention
This invention relates to a hermetically sealed type electronic flash device which is usable under water, and particularly to leak preventing structure.
2. Related Background Art
In a hermetically sealed type electronic flash device usable under water (hereinafter referred to as the underwater stroboscope), means for preventing the entry of water is provided and usually, water does not enter into the underwater stroboscope, whereas should water enter into the underwater stroboscope, the user of the underwater stroboscope will become exposed to a danger such as an electric shock by high-tension light emitting energy stored in the underwater stroboscope. Accordingly, as shown in Japanese Laid-Open Utility Model Application No. 51-133276, whenever water has entered into the underwater stroboscope, alarm display has been effected to inform the user of the entry of water.
However, in the prior-art underwater stroboscope, if the user does not notice the alarm display against the entry of water, electrolysis takes place in the underwater stroboscope by the water which has entered thereinto, and hydrogen gas and oxygen gas are produced as follows: EQU 2H.sub.2 O.fwdarw.2H.sub.2 +O.sub.2.
On the other hand, during the light emission of the underwater stroboscope, a trigger voltage of several thousand volts is applied to a light emission tube prior to the light emission and therefore, when the interior of the underwater stroboscope has been filled with the above-mentioned gases, there has been the danger of the stroboscope being exploded during the application of said trigger voltage.